Game engines with object programming

I started writing apps for iPhone at the end of last year and have an app in the store which is doing reasonably well. I wanted to move into games and have been messing around with OpenGL but am a bit stuck.

What I'm after is recommendations on books or media which can explain the game engine design process with OOP. I've written games for other platforms in various 'basic' languages but they are all procedural and creating a game loop is fairly straight forward. But the move to iPhone and OOP has really confused me.

Can anyone suggest any websites / books / other media which cover how best to structure a game engine for iPhone?

Well if you want books, any of the iPhone game programming books on Amazon will probably help you just fine. But also, if you look at any examples, you can see the techniques there too. Apple used to have a few sample games available.